围产期母体染毒双酚A对雄性子代脑内雌激素β受体和芳香酶表达的影响

为了探讨环境雌激素双酚A (bisphenol-A,BPA)对子代发育期脑内雌激素受体(estrogen receptor,ER）和芳香化酶P450arom表达的影响,对妊娠第7天至哺乳期(仔鼠出生后21天)的母鼠灌胃染毒BPA(200、50、5、0.5mg·kg-1/d),用Western-blot法分别检测出生后4、7、14、21、56天雄性仔鼠的海马及前皮层ERβ和P450arom蛋白表达。结果显示,BPA剂量依赖性地上调前皮层和海马P450arom表达,抑制ERβ蛋白表达。在皮层,出生后4~56天各时间点的P450arom和ERβ表达对BPA都很敏感,其中200、50 或5mg·kg原1/d BPA组与对照组相比有显著差异(P＜0.05,P＜0.01 或P＜0.001);在海马内,BPA对生后发育早期P450arom和ERβ表达的影响更为明显,出生后2周内,200 和50mg·kg-1/d BPA组与对照组相比有显著差异(P＜0.05,P＜0.01或P＜0.001)。以上结果提示,母体围产期BPA暴露可通过上调P450arom而促进雄性子鼠皮层和海马的雌激素合成,并由此抑制ERβ表达。这可能是BPA影响雄性子代脑发育的机制之一。     

雌激素快速影响大鼠发育期海马NMDA受体活性的机制

为了探讨雌激素对发育期大鼠海马NMDA受体活性的快速影响,对出生后18d的雄性大鼠进行苯甲酸雌二醇皮下注射,1h后用WesternBlot检测海马NMDA受体NR1和NR2B亚基、雌激素β受体、ERK1/2蛋白的表达,以及NR2B和ERK1/2的磷酸化水平;并通过海马内给予雌激素受体拮抗剂ICI182,780和MEK1/2抑制剂U0126预处理,进一步分析苯甲酸雌二醇影响NR2B和ERK1/2磷酸化的作用机制。结果显示,苯甲酸雌二醇不影响NR1、NR2B、ERβ和ERK1/2的表达,但能快速增强NR2B和ERK1/2的磷酸化水平。雌激素受体拮抗剂ICI182,780和MEK1/2抑制剂U0126均能明显抑制苯甲酸雌二醇诱导的NR2B和ERK1/2磷酸化水平的增加。以上结果提示,雌激素可能通过雌激素受体的非基因组机制激活ERK/MAPK信号转导通路,快速诱导NMDA受体NR2B亚基磷酸化,激活NMDA受体。     

癫痫大鼠海马NMDA受体亚基NR2A和BDNFmRNA水平的检测

目的通过锂一匹罗卡品癫痫模型（ithium—pilocarpine seizures rats model of epilepsy,LPS）,研究NMDA受体亚基NR2A、BDNF mRNA的表达,探讨NR2A、BDNF在LPS中的作用。方法建立氯化锂-匹罗卡品大鼠模型,运用原位杂交技术检测致痫后各组不同时间点海马CAI、CA3及DG区NR2A与BDNF mRNA的表达。结果LPS海马NR2A、BDNF mRNA在各观察时间点及部位模型组与正常对照组比较均有明显上调,且有显著统计学差异（P〈0．05）。模型组NR2A mRNA的表达上调7d达峰值（P〈0．05）;而BDNF mRNA表达上调14d达峰值。VPA干预组NR2A mRNA在大鼠海马不同时间及部位（除1d的CA3区）的表达较模型组明显下调（P〈0．05）;BDNF mRNA在大鼠海马不同时间及部位（除28d的DG区）的表达较模型组明显下调（P〈0．05）。结论锂－匹罗卡品腹腔注射可诱导大鼠海马NR2A和BDNF mRNA的表达明显上调;NR2A mRNA表达的增强可能是诱导调控BDNF mRNA表达增强的重要机制之一,说明NMDA受体亚基NR2A可能成为抑制癫痫发作的新靶点。     

芝麻素抑制NMDA诱导的小鼠皮层神经元损伤

目的:研究芝麻素对NMDA所致原代培养小鼠皮层神经元损伤的保护作用及其机制。方法:体外培养原代皮层神经元;免疫荧光染色鉴定细胞纯度;MTT法测定细胞存活率;Hoechst/PI双染色观察细胞凋亡的形态学变化;激光共聚焦显微镜技术观察钙成像,检测细胞内钙离子浓度变化;Western blot检测各组细胞中Bcl-2、Bax、NR2A、NR2B蛋白的表达。结果:NMDA(200μM)60分钟能使神经元细胞存活率显著下降,细胞凋亡百分比明显增加(P0.01),芝麻素(0.1μM)能提高细胞存活率,减少细胞凋亡(P0.01)。与NMDA组相比,芝麻素能抑制钙超载;降低Bax和NR2B蛋白表达;增加和Bcl-2蛋白表达(P0.01)。结论:芝麻素具有神经保护作用,这种作用可能与抑制钙超载、下调NMDA受体亚型NR2B的表达以及调节Bcl-2家族蛋白有关。     

NMDA型谷氨酸受体在骨祖细胞和成骨细胞表达并介导力学信号转导

目的：鉴定骨髓间充质干细胞D1和成骨细胞MC3T3-E1、MC3T3-E1亚克隆14是否表达NMDA型谷氨酸受体（NMDAR）,并初步探讨NMDAR是否参与力学信号转导。方法：采用RT—PCR技术、免疫荧光染色技术、蛋白免疫杂交技术和体外细胞循环拉伸装置,鉴定了上述3个细胞系中NMDAR的表达情况,并初步探讨了在MC3T3-E1亚克隆14细胞系中,NMDAR在力学信号转导中的可能作用。结果：3个细胞系均表达NMDA受体亚基1（NR1）和不同的亚基2（NR2A—NR2D）。细胞微丝骨架的破坏并没有阻断力学应变诱导的c-jun、C—fos的表达上调;而阻断NMDAR后,却抑制了力学应变诱导的c-jun、C—fos和成骨细胞特异的转录因子Cbfa1／Runx2的表达上调。结论：NMDAR在骨中表达并发挥功能,参与了骨的力学信号转导过程。     

锌离子调节皮质酮对原代培养大鼠海马神经元的损伤

探讨皮质酮对原代培养大鼠海马神经元的损伤效应及锌的调节作用。用原位染色和RT-PCR方法,分别检测神经元的损伤情况及NMDA受体三种亚基(NRl、NR2A、NR2B)mRNA的表达。皮质酮(5μmol／L)作用2,4h可明显降低海马神经元的存活率,导致神经元凋亡,并随着作用时间的延长而加重;锌离子明显影响皮质酮对海马神经元的损伤效应：同时加入皮质酮和低、中浓度Zn^2 (10、100μmol／L),可明显降低神经元凋亡率,而加入高浓度Zn^2 (250μmol／L)则加重神经元损伤。皮质酮作用24h后,海马神经元NRl、NR2BmRNA的表达水平增高,而同时加入低、中浓度Zn^2 (10、100μmol／L)的海马神经元NRl、NR2BmRNA表达水平与对照组接近;NR2AmRNA表达无明显变化。这些结果表明,锌对皮质酮所致应激损伤的调节具有双向性;NMDA受体亚基水平的变化可能是其中重要环节之一。     

宽频噪音对谷氨酸中毒损伤AD模型大鼠不同脑区NMDAR1(ζ1)、NMDAR2A(ε1)亚基表达的影响

目的:观察AD大鼠模型颞叶和额叶在98 dB宽频噪音暴露5 min后不同脑区NMDAR1(ζ1)、NMDAR2A(ε1) 表达的影响.方法: 采用Western Blot及 RT-PCR技术,结合ABR测定方法.结果:①AD模型组大鼠、空白对照组大鼠在98 dB宽频噪音暴露5 min后额叶、颞区、海马及小脑NMDAR1(ζ1)亚基表达无明显差异,但AD模型组表达明显弱于空白对照组;②生理盐水组加噪音后NMDAR1(ζ1)亚基小脑表达最强,颞叶最弱; NMDAR2A(ε1)表达最强为颞叶,海马最弱.③在海马三组大鼠NMDAR1(ζ1) 、NMDAR2A(ε 1)亚基表达有较明显的下调趋势;④空白对照组大鼠NMDAR1(ζ1)、NMDAR2A(ε1)亚基mRNA表达各区无差异.⑤AD模型组大鼠颞叶、海马NMDAR2A(ε1) 表达明显减弱 ,最弱为小脑,额叶次之.结论:噪音刺激抑制AD大鼠模型海马NMDAR1(ζ1)亚基表达,且不在mRNA水平.噪音刺激抑制AD模型大鼠颞叶、海马NMDAR2A(ε1) 亚基表达,且有部位差异,在mRNA水平已调节.     

心脑佳配方对慢性酒精中毒大鼠学习记忆及海马NMDA受体亚基NR2B表达的影响

目的：研究心脑佳配方对慢性酒精中毒大鼠学习记忆及海马N-甲基-D-天冬氨酸（NMDA）受体2B亚基（NR2B）表达的影响。方法：建立大鼠慢性酒精中毒模型,分别检测学习与记忆成绩、超氧化物歧化酶（SOD）活性和海马区NR2B mRNA表达。结果：学习记忆测试显示模型组大鼠学习记忆成绩比正常组明显下降（P〈0.01）,各用药组与模型组相比,学习记忆成绩明显上升（P〈0.05或P〈0.01）;模型组大鼠脑组织中SOD活性较正常组显著降低（P〈0.01）,而各用药组与模型组相比,脑组织中SOD活性显著升高（P〈0.05或P〈0.01）;PCR结果表明模型组大鼠海马区NR2B mRNA表达较正常组明显上升（P〈0.01）,各用药组与模型组相比,NR2B mRNA表达明显下降,差异有显著性（P〈0.01）。结论：心脑佳配方可能通过对NMDA受体亚基NR2B蛋白表达的调节而发挥抗酒精中毒作用。     

血管性痴呆大鼠海马NR2B受体与学习记忆的研究进展

学习与记忆作为机体的高级神经活动,其产生依赖于神经细胞之间的网络联系,尤其是海马和皮层区域,并且涉及多种受体,如门冬氨酸型受体和谷氨酸受体(NMDARs和AMPARs),而其中NMDA受体的NR2B亚基在突触传递过程起到很重要的作用,其相应基因被称为聪明基因,在突触可塑性和相关的学习记忆中的作用尤为是重要。现根据近年来对NR2B受体与学习记忆的研究进展予以综述。     

NMDA受体与中枢神经系统的发育

离子型谷氨酸受体分为NMDA型和非NMDA型两类,其中NMDA型受体与中枢神经系统发育关系密切。本文综述了NMDA受体的分子特性及NMDA受体五种亚单位NR1、NR2A、NR2B、NR2C和NR2D在动物出生后脑内的时空表达;NMDA受体亚单位在发育中的作用以及NMDA受体活性的胞内调节机制。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418